U.S. Pat. No. 4,066,025 issued Jan. 3, 1978 discloses a semi-automatic hemming machine for folding cloth pieces with the edge folded back within the fold, stitching the folded cloth pieces to form hems, thereon and stacking the stitched hemmed pieces into bundles for further processing. The folding and hemming machine utilizes a conveyor belt for transporting the cloth pieces continuously past stationary folding guide plates, and a pair of synchronized narrow belts engage the folded edge of the material top and bottom to frictionally drive the folded hem through the folding and stitching operations.
At the inception of the folding operation a panel of the material to be hemmed is manually laid on the conveyor belt with the margin of the material to be hemmed overlying the edge of the conveyor by suitable amount sufficient to form the complete hem. As the panel advances, its leading edge is first engaged by the end of an overlying narrow belt located immediately above the marginal edge of a track plate on which the conveyor belt is supported so that the material panel is driven from the underside by the main conveyor belt and from the top by the narrow belt along the marginal edge. The leading edge of the material next engages a stationary curved guide which leads the material to a folded under position preparatory to its engagement from underneath by a lower narrow belt which is led to a lower clearance level by idler rollers to provide an open space for the material to be folded under by the fixed guide.
Such apparatus has been successfully employed commercially for a number of years in forming hems of the type described. However, certain limitations have been encountered with some types of cloth and in the size of hem which can be successfully processed without deflection of the cloth out of position before securely engaged by folder belts which control and clamp the cloth to form the hem.